Continuous centrifugal separator with pool depth control



Jan. 21, 1969 Q'CONOR 3,423,015

CONTINUOUS CENTRIFUGAL SEPARATOR WITH POOL DEPTH CONTRO Filed Aug. 25, 1967 Sheet of2 F I G INVENTOR Fra/r/z OCO/Zon lw n win ATTORNEYS Jan. 21, 1969 F. OCONOR 3,423,015

CONTINUOUS CENTRIFUGAL SEPARA'IOR WITH POOL DEPTH CONTROL Filed Aug. 23, 1967 Sheet 2 of2,

INVENTOR ATTORNEY Frank O'ConoP v United States Patent 3,423,015 CONTINUOUS CENTRIFUGAL SEPARATOR WITH POOL DEPTH CONTROL Frank OConor, Moline, Ill., assignor to Ametek, Inc., New York, N.Y., a corporation of Delaware Filed Aug. 23, 1967, Ser. No. 662,739 US. Cl. 233-7 Int. Cl. B041) ]/06, 3/00, 5/00 8 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to a horizontal type centrifugal separator and more particularly to an improved arrangement for adjusting the depth of the pool within the separator, for introducing a washing liquid into the rotating tubular element, for accelerating the slurry to the speed of the rotating parts, and for preventing a preliminary separation of the slurry as may occur in the conventional design of an inner bowl. A preliminary separation can clog the feed chamber, preventing operation and necessitating the dismantling of the machine for cleanout.

Horizontal type centrifugal separators have been used for the separation of the solids from a slurry which is introduced into the separator. With slurries having a relatively low solids content, there is often a churning of the slurry during the operation of the separator, thus increasing the difliculty of separating the solids and thus reducing the efficiency of the process. Difficulties have also been encountered since at certain pool depths incoming slurry may mix with separated solids and cause some of the solids to be carried out of the effluent. Such separators are generally provided with a structure for maintaining a constant pond depth. The desirability of adjusting the depth of the pond has been recognized and various arrangements have been devised for this purpose. However, such an adjustment usually requires stopping the operation of the separator and substituting different dam plates for the dam plates installed at the liquid collecting end of the drum. The time required for making this adjustment was unduly long and prolonged the downtime of the separator, thus adding to the inefficiency of the operation.

An object of the present invention is to provide an improved arrangement for adjusting the pool depth of a horizontal type centrifugal separator.

Another object of the invention is to provide a horizontal type centrifugal separator wherein the churning of the slurry is kept to a minimum and washing liquid is introduced into the interior of the rotating tubular element.

In one aspect of the invention, there may be provided a horizontal type centrifugal separator having a relatively long, horizontally disposed drum which is mounted for rotation about a horizontal axis. Within the drum. there is rotatably mounted a separator-conveyor assembly having a cylindrical portion on one end with a tubular element of smaller diameter extending axially therefrom. The tubular element is provided with apertures in its 3,423,015 Patented Jan. 21, 1969 walls and has a conical portion at its other end. The separator-conveyor assembly also comprises a conical member extending over the conical end of the tubular element. A plurality of longitudinally extending radial vanes are mounted on the tubular element between the cylindrical portion and the conical member. A spiral blade or vane is mounted around the cylindrical portion of the separator-conveyor assembly, the radial vanes and the conical member to form a screw conveyor. The drum and separator-conveyor assembly are rotated in the same direction but at different speeds. Slurry is continuously fed into the separator-conveyor assembly between the conical member and the tubular element conical portion through a stationary pipe or tubular member extending axially into the assembly. A second pipe extends coaxially through the first pipe and into the tubular element for introducing a washing liquid therein. At the end of the drum opposite the end into which the slurry is fed, there is formed a liquid collecting chamber. The outer end of the drum at the liquid collecting chamber end has relmov ably mounted thereon a plurality of rings having varying inner diameters, with the inner diameters progressively decreasing away from the drum.

The outer longitudinal edges of the radial vanes are continuous with the outer peripheral surface of the separator-conveyor assembly cylindrical portion and ter-minate above the liquid pond so as not to contact the liquid along the inner wall of the drum and thus create turbulence in the pond.

Other objects, advantages and features of the present invention will be apparent upon reference to the following description and accompanying drawings, which are exemplary.

In the drawings:

FIG. 1 is a longitudinal sectional view taken in a vertical plane of a horizontal type centrifugal separator incorporating the present invention;

FIG. 2 is a view of a portion of FIG. 1 but in enlarged scale, showing the arrangement on the drum for adjusting the pond depth;

FIG. 2A is an enlarged broken view showing the spacer rings of FIG. 2 in a different position;

FIG. 3 is a plan View of one of the adjustable dam rings of FIG. 2; and

FIG. 4 is a transverse sectional view taken along the line 44 of FIG. 2.

Referring to the drawings wherein like reference symbols indicate the same parts throughout the various views, a specific embodiment of the present invention will be described in detail.

The centrifugal separator comprises a relatively long, hollow drum 10 mounted for rotation about a horizontal axis. The drum 10 has a dry end plate 11 mounted on one end thereof, the plate having a housing portion 12 and a shaft 13 extending therefrom which is journaled in a bearing 14. A pulley 15 is mounted on the shaft 13 and is drivingly connected by a belt 1 6 to a source of power for rotating the drum.

A hollow insert 17 of a generally truncated conical form is fastened within the drum 10 and one end thereof may form with a portion of the dry plate or trunnion 11 a collecting chamber 18 for receiving the separated solids. Radial ports 19 are provided in dry trunnion 11 for discharging the collected solids into a chamber 20 located within a housing 21 surrounding the drum 10.

The opposite end of the drum 10 has mounted therein a wet end trunnion 22 having efiluent discharge ports 23 therein and a hollow shaft 24 extending axially therefrom and in alignment with hollow shaft 13. The shaft 24 may be journaled in and extend beyond a bearing 25 which is similar to bearing 14.

Mounted on the outer face of wet trunnion 22 is a mounting ring 26, spacer ring collars 27 and a plurality of dam rings 28 which form a liquid collecting chamber 29. Liquid is discharged through the radial spaces between the spacer collars 27. The dam rings 28 are detachably mounted by stud bolts 28A and have varying inner diameters and a lip surrounding their inner diameters. The rings 28 are positioned so that their inner diameters progressively decrease outwardly from the drum. By positioning a plurality of such dam rings at the wet end of the drum, the depth of the pond may be easily adjusted by changing the position of the spacer collars with respect to the dam rings. For example, by repositioning the outer dam ring and collars, the depth would be decreased to the inner diameter of the outer remaining ring.

The shaft 24 may be provided at its extended end with a gear reducing unit 30 having a plurality of planetary gear stages therein.

Mounted within the drum 10 is a separator-conveyor assembly indicated generally at 31 and comprising a cylindrical portion 32 and a tubular element 33 extending axially therefrom with a tapered or conical end 34. The tubular element is provided with a plurality of openings 35 in which may be mounted nozzles 36. The cylindrical portion 32 may be provided with antifriction bearings 37 so as to be journaled on the inner end of hollow shaft 24, and is attached to a shaft passing through the hollow shaft 24.

A plurality of longitudinally extending radial vanes 38 may be equally spaced about and fixed to the outer periphery of the tubular element 33. These vanes are of a lesser height than the pond depth so as to provide an annular space between their outer longitudinal edges and the inner periphery of the drum 10, so that clarified liquid may pass over the top of the vanes without disturbing previously settled solids.

A hollow conical member 39 may have a base portion suitably fastened to the vanes 38 and includes a hollow shaft extension 40 that is journaled in an antifriction bearing 41 located in the housing portion 12 of end trunnion 11.

A spiral strip or vane 42 surrounds the outer faces of the cylindrical portion 32, the radial vanes 38 and the conical member 39. The strip thus forms a screw conveyor and the spiraling is such that the solids separated from the slurry are moved toward dry end trunnion 11.

A stationary slurry feed tube 43 extends into the conical member 39 and has its outer end supported by a fixture 44. The slurry is introduced through the inlet 45. The feed tube is non-rotatably supported and its longitudinal axis may be in line with the rotational axis of the drum and rotating element. The wall of the feed tube 43 is provided with an opening 46 through which the slurry is discharged within the conical member 39.

Coaxially positioned within feed tube 43 and nonrotatably supported therein is a feed pipe 47 for introducing washing liquid into the rotating element. The feed pipe 47 extends through an opening in conical end 34 into the interior of the tubular element 33. The outer end of feed pipe 47 extends outwardly at 48 and is connected to a source of supply for the washing liquid. Feed pipe 47 is secured at 49 to the end of feed tube 43 so as to be stationary.

In the operation of the separator in accordance with the present invention, the rotation of the pulley 15 will rotate drum 10, and with it gear box 30', in a clockwise direction. Under the action of the planetary gear units therein, the conveyor assembly 31 will also rotate in the same direction as drum 10 but at a lower speed.

The slurry is fed through feed tube 43 and is discharged through opening 46 into the conical member 39. The rotary speed of the slurry is caused to increase as it passes through the throat of conical member 39 so that it is substantially at the rotary speed of the liquid within the pond extending along the length of drum 10 when the slurry reaches the pond. As a result, turbulence is prevented in the pond when it is reached by the slurry, and the slurry is also prevented from contacting dry solids.

The vanes 38 cause centrifugal separation of the solids from the slurry with the solids moving radially outwardly toward the drum and the liquid remaining radially inwardly thereof. The spiral flights 42 of the conveyor move the solids toward the dry end trunnion 11 and they are discharged through ports 19 into the chamber 20.

The liquid continues to move toward the wet end trunnion 22 and is discharged through ports 23 into chamber 29. The depth of the accumulated liquid is regulated by the adjustable dam rings 29 by selecting a dam ring the diameter of which corresponds to the desired depth of the pond.

During this separating operation, washing liquid may be introduced through feed pipe 47 into the rotating element 33 from where it is discharged under centrifugal force through the nozzles 36.

Thus, it can be seen that the present invention provides an improved horizontal type centrifugal separator having an arrangement whereby the depth of the pond may be rapidly changed. There is also provided a stationary feed pipe for introducing washing liquid into the rotating element with the liquid being discharged from the element through openings therein. The heights of the radial vanes are so selected as to terminate above the pond in order not to interfere with the pond during the separating operation.

It is to be understood that various details of construction and arrangement of parts can be changed without departing from the spirit of the invention except as defined in the appended claims.

What is claimed is:

1. In a horizontal type centrifugal separator, a drum mounted for rotation about a horizontal axis, a separatorconveyor assembly having a cylindrical portion with a tubular element of smaller diameter extending axially therefrom, there being a conical portion at the other end of said tubular element and apertures in said tubular element, a conical member at the other end of said separator-conveyor assembly and extending over said tubular element conical end portion, radial vane means extending longitudinally on said tubular element between said cylindrical portion and said conical member, spiral means around said cylindrical portion, said radial vane means and said conical member to form a screw conveyer, means for rotating said drum and separator-conveyor assembly at different speeds, means for continuously feeding slurry into said separator-conveyor assembly between said conical member and said tubular element conical end portion, means for introducing a washing liquid into said tubular element with said liquid being discharged centrifugally therefrom through said apertures, a liquid collecting chamber within said drum at the end thereof opposite from that into which the slurry is fed, and adjstable means at said drum end for adjusting the depth of the pool within said drum.

2. In a horizontal type centrifugal separator as claimed in claim 1 wherein said slurry feeding means comprises a stationary tubular member extending axially into said conical member and terminating short of said tubular element conical end portion.

3. In a horizontal type centrifugal separator as claimed in claim 2 wherein said liquid introducing means comprises a second stationary tubular member extending axially through said first tubular member into said tubular element.

4. In a horizontal type centrifugal separator as claimed in claim 1 wherein said adjustable means comprises a plurality of rings having varying inner diameters.

5. In a horizontal type centrifugal separator as claimed in claim 4 wherein said inner diameters progressively decrease away from said rum.

6. In a horizontal type centrifugal separator as claimed in claim 4 and further comprising means for detachably securing said rings to the end of said drum.

7. In a horizontal type centrifugal separator as claimed in claim 1 wherein the outer longitudinal edges of said radial vane means are continuous with the outer peripheral surface of said separator-conveyor assembly cylindrical portion.

8. In a horizontal type centrifugal separator as claimed in claim 1 and further comprising means on said separa- 10 tor-conveyor assembly forming with said drum a solids chamber and a liquid pool, the outer longitudinal edges of said radial vane means terminating above the liquid pool.

References Cited UNITED STATES PATENTS 1,383,313 7/1921 Landreth 233-7 2,600,372 6/1952 Milliken 233-7 3,096,282 7/1963 Trotter 2337 3,348,767 10/1967 Ferney 2337 ROBERT W. JENKINS, Primary Examiner. 

